The invention relates to a device for imaging layers of a body. The device comprises a plurality of radiation sources which are situated at radiation source positions in a plane, on one side of the body. A radiation detector is situated at the opposite side of the body in order to form perspective images. A reconstruction device superimposes the perspective images in order to form layer images.
A device of this kind is known from an article entitled "Das elektronische Schichtbild" (The electronic layer image) in Rontgenpraxis, Volume 34 (1981), pages 253-257. The device described therein comprises a plurality of X-ray tubes which are arranged in one plane and which can be briefly activated in succession. The radiation beams of the tubes successively irradiate an object to be examined from different perspectives. The separate projections are generated quickly in succession and are superposed in an X-ray image intensifier tube detector by magnetic deflection, so that a layer image of the irradiated object is formed on the exit screen of the X-ray image intensifier tube. Such a device forms a layer image of a body per radiation source cycle. The separate perspective images are not stored in this device.
If several layer images were to be reconstructed from a single set of projection images by means of the known device, storage of the perspective images formed during a source cycle would be necessary. In order to reduce artefacts in the reconstructed layer images, the perspective images used for reconstructing of the layer images may not overlap. This can be achieved in the known device by choosing the angles of aperture of the radiation beams to be so small that the perspective images appearing on the exit screen of the X-ray image intensifier are each situated in separate zones. It is a drawback, however, that only a comparatively small object zone can thus be irradiated.